Image resolution may refer to the amount of detail one or more images hold. The term applies to digital images, video images, film images, and other types of images. Higher-resolution means more image detail, while lower-resolution means less image detail. Image resolution can be measured in a number of ways.
For instance, the resolution of a digital camera can be described in terms of pixel resolution, spatial resolution, spectral resolution, and temporal resolution. Pixel resolution refers to the capability of a sensor to observe or measure the smallest object clearly with distinct boundaries. A pixel is a unit of digital resolution depending upon the size of the pixel. Typically, for any given lens setting, the smaller the size of the pixel, the higher the resolution will be, and the clearer the object in the image. Spatial resolution refers to how closely lines can be resolved in an image, and depends on the properties of the system creating the image, and not just the pixel resolution in pixels per inch. In effect, spatial resolution refers to the number of independent pixel values per unit length. Spectral resolution is the ability to resolve spectral features and bands into their separate components.
Temporal resolution may refer to the precision of a video image stream with respect to time. Often, there is a trade-off between temporal resolution and spatial resolution due to the uncertainty principle, which is an inherent property of Fourier transform. Movie cameras and high-speed cameras can resolve events at different points in time. The time resolution used for movies may be 24 to 48 frames per second (frames/s), whereas a high-speed, high-resolution camera may resolve 50-300 frames/s, or even more. As technology continues to progress, high-resolution video cameras producing high-resolution video data streams continue to become more common. While increased video resolution may have advantages in certain situations, the higher-resolution video data results in increased transmit time and increased storage cost when used, for instance, in a security monitoring system.